41 research outputs found
2+1 flavor QCD with the fixed point action in the -regime
We generated configurations with the approximate fixed-point Dirac operator
on a lattice with fm where the scale
was set by . The distributions of the low lying eigenvalues in different
topological sectors were compared with those of the Random Matrix Theory which
leads to a prediction of the chiral condensate.Comment: 6 pages, 5 figures, presented at the XXV International Symposium on
Lattice Field Theory, July 30 - August 4 2007, Regensburg, German
White and green rust chimneys accumulate RNA in a ferruginous chemical garden
Mechanisms of nucleic acid accumulation were likely critical to life's emergence in the ferruginous oceans of the early Earth. How exactly prebiotic geological settings accumulated nucleic acids from dilute aqueous solutions, is poorly understood. As a possible solution to this concentration problem, we simulated the conditions of prebiotic low-temperature alkaline hydrothermal vents in co-precipitation experiments to investigate the potential of ferruginous chemical gardens to accumulate nucleic acids via sorption. The injection of an alkaline solution into an artificial ferruginous solution under anoxic conditions (O2â<â0.01% of present atmospheric levels) and at ambient temperatures, caused the precipitation of amakinite (âwhite rustâ), which quickly converted to chloride-containing fougerite (âgreen rustâ). RNA was only extractable from the ferruginous solution in the presence of a phosphate buffer, suggesting RNA in solution was bound to Fe2+ ions. During chimney formation, this iron-bound RNA rapidly accumulated in the white and green rust chimney structure from the surrounding ferruginous solution at the fastest rates in the initial white rust phase and correspondingly slower rates in the following green rust phase. This represents a new mechanism for nucleic acid accumulation in the ferruginous oceans of the early Earth, in addition to wet-dry cycles and may have helped to concentrate RNA in a dilute prebiotic ocean
Cytokeratin 8/18 expression indicates a poor prognosis in squamous cell carcinomas of the oral cavity
BACKGROUND: Intermediary filaments are involved in cell motility and cancer progression. In a variety of organs, the expression of distinct intermediary filaments are associated with patient prognosis. In this study, we seeked to define the prognostic potential of cytokeratin and vimentin expression patterns in squamous cell carcinomas (SCC's) of the oral cavity. METHODS: 308 patients with histologically proven and surgically treated squamous cell carcinomas of the oral cavity were investigated for the immunohistochemical expression of a variety of intermediary filaments including high- and low-molecular weight cytokeratins (Ck's), such as Ck 5/6, Ck 8/18, Ck 1, CK 10, Ck 14, Ck 19 and vimentin, using the tissue microarray technique. Correlations between clinical features and the expression of Cytokeratins and vimentin were evaluated statistically by Kaplan-Meier curves and multivariate Cox regression analysis. RESULTS: The expression of Ck 8/18 and Ck 19 were overall significantly correlated with a poor clinical prognosis (Ck 8/18 p = 0.04; Ck19 p < 0.01). These findings could also be reproduced for Ck 8/18 in primary nodal-negative SCC's and held true in multivariate-analysis. No significant correlation with patient prognosis could be found for the expression of the other cytokeratins and for vimentin. CONCLUSION: The expression of Ck 8/18 in SCC's of the oral cavity is an independent prognostic marker and indicates a decreased overall and progression free survival. These results provide an extended knowledge about the role of intermediary filament expression patterns in SCC's
Science and Ethics from the German Perspective: An Annotated Bibliography, 1965 -- 1976
Weingart P, Eberwein W-D. Science and Ethics from the German Perspective: An Annotated Bibliography, 1965 -- 1976. Newsletter on Science, Technology and Human Values. 1977;20:25-38
The relevance of the EERQI framework in the light of future perspectives: Enhancing the visibility and detection of European research publications
Rolled concrete: Results from the most recent research and many years of practice
Walzbeton ist ein erdfeuchter Beton, der mit ĂŒblichen StraĂenfertigern eingebaut und mit Walzen verdichtet wird. Er erreicht eine groĂe Druckfestigkeit und OberflĂ€chenfestigkeit sowie hohe VerformungsstabilitĂ€t und TragfĂ€higkeit. Walzbeton wird im klassifizierten StraĂenbau als Tragschicht mit einer dĂŒnnen AsphaltĂŒberdeckung oder als direkt befahrene Tragdeckschicht fĂŒr IndustrieflĂ€chen, WerkstraĂen oder lĂ€ndliche Wege verwendet. Anforderungen sind im "Merkblatt fĂŒr den Bau von Tragschichten und Tragdeckschichten mit Walzbeton fĂŒr VerkehrsflĂ€chen" enthalten. In Laborversuchen mit Walzbeton wurde festgestellt, dass die Druckfestigkeit bei abnehmendem Hohlraumgehalt und im allgemeinen mit zunehmendem Zementgehalt und dadurch - bei annĂ€hernd gleichbleibendem optimalem Wassergehalt - abnehmendem w/z-Wert gröĂer wurde. Auch bei niedrigem Verdichtungsgrad von nur 96 Prozent der modifizierten Proctordichte erreichten Walzbetone mit ausreichendem Zementgehalt von mindestens 240 kg/m3 die fĂŒr Tragdeckschichten geforderte Druckfestigkeit von mindestens 40 N/mm2. Bei niedrigen Zementgehalten und bei Ersatz von Zement durch Steinkohlenflugasche wurde eine anforderungsgerechte Druckfestigkeit erst bei sehr sorgfĂ€ltiger Verdichtung auf einen Verdichtungsgrad von mehr als 98 Prozent erreicht. Die Abwitterung bei Frostbeanspruchung lag beim Walzbeton unabhĂ€ngig von der Zuschlagart und dem Zementgehalt deutlich unter dem fĂŒr ausreichend hohen Frost-Tau-Widerstand ĂŒblicher Betone festgelegten Grenzwert. Einen ausreichend hohen Frost-Tau-Widerstand erreichte der untersuchte Walzbeton mit Zugabe von Luftporenbildner unabhĂ€ngig vom Zusatzstoff und ohne Luftporenbildner, wenn ein hoher Zementgehalt von 270 kg/m3 und zusĂ€tzlich Basaltmehl als Zusatzstoff zugesetzt wird. Mit dem CBR-Versuch können Aussagen ĂŒber die GrĂŒnstandfestigkeit von Walzbeton und die Art des Herstellens der Kerben gemacht werden, wofĂŒr aber noch keine Bewertungskriterien angegeben werden können. Im Rahmen des Baues einer Ortsumgehung einer BundesstraĂe wurde eine Versuchsstrecke mit Walzbetontragschicht unterschiedlicher Dicke und dĂŒnner AsphaltĂŒberdeckung eingerichtet. Zustand und die QualitĂ€t der Schichten wurden dokumentiert und dienen als Grundlage fĂŒr Untersuchungen des Langzeitverhaltens. Mit den ermittelten Werkstoffkennwerten kann das Verhalten des Walzbetons beschrieben werden. Aufgrund der Untersuchungen sollte die Walzbeton-Tragschicht einlagig eingebaut werden und die Dicke 20 cm nicht ĂŒberschreiten. Der Abstand der Querkerben sollte 3,0 m betragen, um eine kleine Kerbenöffnung und damit eine bessere Rissverzahnung und QuerkraftĂŒbertragung zu erreichen. Bisher zeigte die von Verkehr befahrene Versuchsstrecke ein gutes Verhalten. Die bisherigen Forschungsergebnisse sind in die Ăberarbeitung des Merkblatts fĂŒr Walzbeton eingeflossen. Der Bericht umfasst folgende Teile: Kompendium (Birmann,D; Burger,W; Weingart,W; Westermann,B); Teil 1: Einfluss der Zusammensetzung und der Verdichtung von Walzbeton auf die Gebrauchseigenschaften (1) (Schmidt,M; Bohlmann,E; Vogel,P; Westermann,B); Teil 2: Einfluss der Zusammensetzung und der Verdichtung von Walzbeton auf die Gebrauchseigenschaften (2) (Weingart,W; Dressler,F); Teil 3: Messungen an einer Versuchsstrecke mit Walzbeton-Tragschicht an der B54 bei Stein-Neukirch (Eisenmann,J; Birmann,D); Teil 4: Temperaturdehnung, Schichtenverbund, vertikaler Dichteverlauf und Ebenheit von Walzbeton (Burger,W).Rolled concrete is a no-slump concrete which is applied with the usual road finisher and compacted with rollers. lt attains great compressive and surface strength, is very resistant to deformation and has a high bearing capacity. Rolled concrete is used in classified road construction as a base course with a thin asphalt cover or as a combined wearing / base course for industrial areas, roads on company premises or rural roads; in the latter cases it is then driven on directly. The requirements are contained in the "Guidelines for the construction of base courses and combined wearing / base courses with rolled concrete for traffic surfaces". Laboratory tests with rolled concrete showed that, as the voids content decreased and, generally, as the concrete content increased and thus - the water content remaining approximately at the same Optimum level - with a decreasing water-cement value, the compressive strength became greater. Rolled concretes with a sufficient cement content of at least 240 kg/m3 achieved the compressive strength required of combined wearing / base courses of at least 40 N/mm2 even at a low compaction level of only 96% of the modified proctor density. With a low cement content, a compressive strength level high enough to meet the requirements was only attained through very careful compression to a level of more than 98%. The degree of weathering caused when the rolled concretes were subjected to stress and strain through frost, was, with all types of aggregate and all levels of cement content, well below the limit values laid down for a sufficiently high resistance to freezing and thawing for normal types of concrete. When an air-entraining agent was added the rolled concrete investigated attained a sufficiently high resistance to freezing and thawing regardless of the additive used; when an air-entraining agent was added the rolled concrete investigated attained a sufficiently high resistance to freezing and thawing with a high cement content of 270 kg/m3 and the addition of basalt meal. Using the CBR test, statements can be made on the green bond of rolled concrete and the type of manufacture of the notches; however, no evaluation criteria can yet be given for this. A test route was incorporated into the construction of a by-pass; this test route consisted of a rolled concrete base course of differing thickness and a thin asphalt surface. The state and quality of the courses were documented and serve as a basis for investigations of long-term behaviour. The material parameters recorded can be used to describe the behaviour of rolled concrete. Based on the investigations the rolled concrete base course should be single-layered and should not be more than 20 cm thick. The distance between the latitudinal notches should be 3.00 metres in order that the notches open only to a small degree which allows a better dovetailing of the cracks and a better transfer of transverse forces. The test route driven on by traffic has behaved well thus far. The research results arrived at so far have been incorporated into the revision of the Guidelines for rolled concrete. There are a number of appendices attached to the original reports. These contain inter alia detailed descriptions of the recipes investigated and representations of the investigation results e.g. individual and mean values for CBR values, volume weight, compressive strength, mass loss and behaviour under temperature and stress. A detailed presentation and evaluation is given of the binders, additives and aggregates and their reactions as a function of the various recipes used. These appendices have been omitted from the present publication. They can be consulted at the Federal Highway Research Institute. References to these appendices in the text have therefore been retained
Erst denken, dann handeln? Wissenschaftliche Politikberatung aus der Perspektive der Wissens(chafts)soziologie
Weingart P. Erst denken, dann handeln? Wissenschaftliche Politikberatung aus der Perspektive der Wissens(chafts)soziologie. In: Falk S, Rehfeld D, Römmele A, Thunert M, eds. Handbuch Politikberatung. Wiesbaden: VS Verlag fĂŒr Sozialwissenschaften; 2006: 35-44
Early Loading of Sandblasted and Acid-Etched Titanium Implants in the Edentulous Mandible: A Prospective 5-Year Study
Die Cozitationsanalyse als bibliometrisches Verfahren zur Messung der nationalen und institutionellen Forschungsperformanz.
Winterhager M, Weingart P, Sehringer R. Die Cozitationsanalyse als bibliometrisches Verfahren zur Messung der nationalen und institutionellen Forschungsperformanz. In: Daniel H-D, Fisch R, eds. Evaluation von Forschung: Methoden, Ergebnisse, Stellungnahmen. Konstanzer BeitrÀge zur sozialwissenschaftlichen Forschung. Vol 4. Konstanz: Univ.-Verl. Konstanz; 1988: 319-358